In general, electricity is a type of essential energy that has become a part of life in modern society. Electrical energy is already being obtained by various methods, such as thermal power, water power, nuclear power generation, and the like, and has excellent properties. However, there are many problems, such as the exhaustion of resources by ongoing energy generation and the resultant limits of energy generation, high cost, and the environmental pollution caused by power generation systems. Therefore, countries aware of such problems have recently attempted to steadily increase their investment in developing alternative energies. For example, power generation apparatuses using sunlight as an alternative energy source have been intensively developed. These power generation apparatuses are constituted of solar cells adapted to directly receive the sunlight, and can charge a voltage generated from the solar cells into a storage battery through a constant voltage circuit that constantly maintains the voltage of the solar cells, such that the storage battery can be used as an auxiliary power supply when needed.
However, disadvantages of the power generation using the solar cells include low efficiency, there being a great difference in the amount of electricity generated relative to the quantity of sunlight, and not generating electricity at night. Thus, such power generation cannot serve as a primary energy source in some countries, but only as an auxiliary or experimental energy source.
In addition, energy generation apparatuses using tidal power, wind power, or water power generation can be used as an auxiliary power supply only in regions having the proper natural conditions. Therefore, such energy generation apparatuses can generate a lower voltage than those expected, be largely subject to restrictions with respect to the surrounding environment, and require too much initial plant investment. As a result, energy generation apparatuses cannot be considered as being common.
Therefore, the interest in using energy recycling as a further alternative energy has increased. Accordingly, the present invention is devised to convert vibrational energy generated by a bridge into electrical energy by using energy recycling to supply the electric power needed by the bridge.
According to a recent report, there are approximately 23,000 bridges throughout South Korea and this number will increase more in future. Also, the scale and length of bridges are being gradually increased. The structure of such bridges has a deck plate installed on top of piers and the bridges are subject to dynamic loads which vary by the minute because vehicles and like pass at high speed over the bridge. For big bridges, since the length of the deck plate is increased, an expansion length of the deck plate due to thermal deformation in response to temperature changes depending on a change in the seasons can also increase. Therefore, such big bridges have to be designed to allow there to be relative motion in contact portions between the deck plate and the piers. Also, in case a great impact force should be applied to the bridges in a horizontal direction due to an earthquake, the support structure of the bridges needs to be able to alleviate and reduce the impact forces in the horizontal direction. For this purpose, the bridges have resilient supports installed between the deck plate and the piers to support the deck plate while responding to displacement of the deck plate, such that the impact forces applied to the deck plate can be reduced.
Each resilient support of the bridges as described above is configured to reduce the impact force occurring on the bridges and generates vibrational energy due to the impact forces occurred on the bridges and transfers it unchanged to the resilient support.
However, according to the related art, the resilient support, to which the vibrational energy generated by the load of the deck plate of the bridge and the passage of vehicles are transferred, only reduces the impact force of the vibration energy, and wastes the vibration energy without recycling it.